From b3a12c62c9085171866256f00dada4326a4a3084 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Sat, 20 Apr 2019 09:31:47 -0700 Subject: [PATCH] Improve XDG_RUNTIME_DIR diagnostic * lib-src/emacsclient.c (set_local_socket): If there appears to be an XDG runtime directory for the user but XDG_RUNTIME_DIR is unset, suggest setting it while warning about potential security issues (Bug#35300). --- lib-src/emacsclient.c | 28 +++++++++++++++++++++++----- 1 file changed, 23 insertions(+), 5 deletions(-) diff --git a/lib-src/emacsclient.c b/lib-src/emacsclient.c index f476840898..5871a18ce6 100644 --- a/lib-src/emacsclient.c +++ b/lib-src/emacsclient.c @@ -1357,6 +1357,7 @@ set_local_socket (char const *server_name) int tmpdirlen = -1; int socknamelen = -1; uid_t uid = geteuid (); + bool tmpdir_used = false; if (strchr (server_name, '/') || (ISSLASH ('\\') && strchr (server_name, '\\'))) @@ -1389,6 +1390,7 @@ set_local_socket (char const *server_name) } socknamelen = local_sockname (sockname, socknamesize, tmpdirlen, uid, server_name); + tmpdir_used = true; } } @@ -1462,11 +1464,27 @@ set_local_socket (char const *server_name) if (sock_status < 0) message (true, "%s: Invalid socket owner\n", progname); else if (sock_status == ENOENT) - message (true, - ("%s: can't find socket; have you started the server?\n" - "%s: To start the server in Emacs," - " type \"M-x server-start\".\n"), - progname, progname); + { + if (tmpdir_used) + { + uintmax_t id = uid; + char sockdirname[socknamesize]; + int sockdirnamelen = snprintf (sockdirname, sizeof sockdirname, + "/run/user/%"PRIuMAX, id); + if (0 <= sockdirnamelen && sockdirnamelen < sizeof sockdirname + && euidaccess (sockdirname, X_OK) == 0) + message + (true, + ("%s: Should XDG_RUNTIME_DIR='%s' be in the environment?\n" + "%s: (Be careful: XDG_RUNTIME_DIR is security-related.)\n"), + progname, sockdirname, progname); + } + message (true, + ("%s: can't find socket; have you started the server?\n" + "%s: To start the server in Emacs," + " type \"M-x server-start\".\n"), + progname, progname); + } else message (true, "%s: can't stat %s: %s\n", progname, sockname, strerror (sock_status)); -- 2.17.1